Manufactured at the RoF at Fazakerley (just outside Liverpool)

 

Perfect, thank you. Any idea on the black powdery residue? Is that original finish coming off or did someone paint/attempt a refinish.

 

If it comes off that easily, wipe it down with mineral spirits. When it stops coming off, then oil it as you normally would.

 

Thank you, I assume any old CLP to keep it protected?

 

British No 4 production factories were assigned the first digit to use in the serial number. Maltby = 1, Fazakerley = 2, BSA Shirley = 3. There are some early outliers but that's a general rule of thumb.

 

The black schmootz is "stoving" or the remains of it, or perhaps someone's attempt to re-create the British propensity to paint all metal black, customarily called by that name.